1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* nommu.c: mmu-less memory info files 3 * 4 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #include <linux/init.h> 9 #include <linux/module.h> 10 #include <linux/errno.h> 11 #include <linux/time.h> 12 #include <linux/kernel.h> 13 #include <linux/string.h> 14 #include <linux/mman.h> 15 #include <linux/proc_fs.h> 16 #include <linux/mm.h> 17 #include <linux/mmzone.h> 18 #include <linux/pagemap.h> 19 #include <linux/swap.h> 20 #include <linux/smp.h> 21 #include <linux/seq_file.h> 22 #include <linux/hugetlb.h> 23 #include <linux/vmalloc.h> 24 #include <linux/uaccess.h> 25 #include <asm/tlb.h> 26 #include <asm/div64.h> 27 #include "internal.h" 28 29 /* 30 * display a single region to a sequenced file 31 */ 32 static int nommu_region_show(struct seq_file *m, struct vm_region *region) 33 { 34 unsigned long ino = 0; 35 struct file *file; 36 dev_t dev = 0; 37 int flags; 38 39 flags = region->vm_flags; 40 file = region->vm_file; 41 42 if (file) { 43 struct inode *inode = file_inode(region->vm_file); 44 dev = inode->i_sb->s_dev; 45 ino = inode->i_ino; 46 } 47 48 seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); 49 seq_printf(m, 50 "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", 51 region->vm_start, 52 region->vm_end, 53 flags & VM_READ ? 'r' : '-', 54 flags & VM_WRITE ? 'w' : '-', 55 flags & VM_EXEC ? 'x' : '-', 56 flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p', 57 ((loff_t)region->vm_pgoff) << PAGE_SHIFT, 58 MAJOR(dev), MINOR(dev), ino); 59 60 if (file) { 61 seq_pad(m, ' '); 62 seq_file_path(m, file, ""); 63 } 64 65 seq_putc(m, '\n'); 66 return 0; 67 } 68 69 /* 70 * display a list of all the REGIONs the kernel knows about 71 * - nommu kernels have a single flat list 72 */ 73 static int nommu_region_list_show(struct seq_file *m, void *_p) 74 { 75 struct rb_node *p = _p; 76 77 return nommu_region_show(m, rb_entry(p, struct vm_region, vm_rb)); 78 } 79 80 static void *nommu_region_list_start(struct seq_file *m, loff_t *_pos) 81 { 82 struct rb_node *p; 83 loff_t pos = *_pos; 84 85 down_read(&nommu_region_sem); 86 87 for (p = rb_first(&nommu_region_tree); p; p = rb_next(p)) 88 if (pos-- == 0) 89 return p; 90 return NULL; 91 } 92 93 static void nommu_region_list_stop(struct seq_file *m, void *v) 94 { 95 up_read(&nommu_region_sem); 96 } 97 98 static void *nommu_region_list_next(struct seq_file *m, void *v, loff_t *pos) 99 { 100 (*pos)++; 101 return rb_next((struct rb_node *) v); 102 } 103 104 static const struct seq_operations proc_nommu_region_list_seqop = { 105 .start = nommu_region_list_start, 106 .next = nommu_region_list_next, 107 .stop = nommu_region_list_stop, 108 .show = nommu_region_list_show 109 }; 110 111 static int __init proc_nommu_init(void) 112 { 113 proc_create_seq("maps", S_IRUGO, NULL, &proc_nommu_region_list_seqop); 114 return 0; 115 } 116 117 fs_initcall(proc_nommu_init); 118